The 8400 series is the direct descendant of the original MP (manipulation proof) lock. 8410-009 is UL listed group 1. Typically furnished with D41/R162 dial and ring priced separately. Specify 8410-100 to order the set. Pictured with plastic wheels, however, the 8410 series has brass wheels.

The 8400 series is the direct descendant of the original MP (manipulation proof) lock. 8430-002 is UL listed group 1R. Typically furnished with D41/R162 dial and ring priced separately. To order the set, specify 8430-101. Group 1R locks have plastic wheels, as pictured.